Dehumidifier desiccant cartridge



United States Patent 3,338,032 DEHUMIDIFIER DESICCANT CARTRIDGE Robert M. Siewert, US. Army, assignor to the United States of America as represented by the Secretary of the Army Filed Apr. 12, 1966, Ser. No. 542,122 1 Claim. (Cl. 55-162) ABSTRACT OF THE DISCLOSURE This invention is directed to an expendable cartridge in a dehumidifier for equipment which requires that humidity be kept within narrow limits, such as a wave guide or some other electronic equipment or in a missile. Further, the dehumidifier which makes use of this cartridge provides for continuous operation by employing a pair of cartridges one of which is used to dehumidify an air flow while the other is being dried of its absorbed moisture desiccated during its time of dehumidifying the air flow. The contributions of this invention incorporated in the structure of the cartridge to render it expendable are: provide interchangeability of cartridges so that only one type of cartridge need by made for ready adaptation to either of the two positions in the dehumidifier; aiford a sealed cartridge that provides maximum moisture absorption within the cartridge; and provide a flow valve with a capillary hole to eliminate the cumbersome and vulnerable-to-damage capillary tubes of the prior art.

This invention may be made or used by or for the Government of the United States of America without any payment to me of any royalty thereon.

This invention relates in general to dehumidifiers and, more particularly, to a dehumidifier desiccant cartridge.

Accordingly, it is an object of this invention to provide a unique expendable cartridge for a dehumidifier.

Another object of this invention is to provide a sealed cartridge in a dehumidifier.

Still another object of this invention is to provide an interchangeable cartridge in a dehumidifier which requires two cartridges.

A further object of this invention is to provide a flow valve which does not require a fragile capillary tube exterior thereof.

The exact nature of this invention as well as other objects and advantages thereof will be readily apparent from consideration of the following specification relating to the annexed drawing in which:

FIGURE 1 is a schematic showing the system which includes the expendable cartridge of this invention;

FIGURE 2 shows the cartridge and flow valve of this invention in section; and

FIGURE 3 shows the exploded elements of section 2 in pictorial form.

In the system shown in FIGURE 1, a controlled humidity chamber has a dehumidifier 11 which maintains the humidity level within a very narrow limit. Since the humidity control is for relatively long periods of time, two desiccant cartridges 12 and 13 are employed and a sequence timer 14 controls input solenoid operated three way valves 15 and 16 to alternately direct the air flow through one of the cartridges and to apply heat to the other cartridge thereby removing the absorbed moisture therefrom. By this method the moisture saturation level of the desiccant material is never reached and constant humidity control is assured. Flow valves 17 and 18 are provided at the output ends of the cartridges to prevent full backflow through the cartridge being heated while providing enough backflow to remove the moisture from the heated desiccant through the three way valve 15 or 3,338,032 Patented Aug. 29, 1967 1-6 as applicable. The several components of the system are connected by the fluid conductors 19 through which the fluid flows in the direction indicated by the arrows. The timing of the cycle, controlled by sequence timer 14, is determined by the requirements of the system to assure that the absorption level of the desiccant in the desiccating cartridge is always suflicient to meet demand.

In FIGURE 2, cartridge 12 is shown encased in container 21 which isolates the cartridge from the rest of the system. The cartridge 12 is mounted within the container 21 by a bolt 22 connected at one end thereof and is inserted through a hole in the end of container 21 and secured thereto by a nut 23. Bolt 22 is provided with a fluid flow channel through its interior to exhaust the dried fluid from a cartridge. The head portion 24 of cartridge 12 has a peripheral dimension which snugly fits within the open end of container 21. The exterior configuration of container 21 is usually cylindrical. Other shapes are applicable as long as the head end 24 and body 25 are shaped to conform thereto. Cartridge 12 has a cylindrical body 25 which is dimensioned so as to receive a blankettype heater 26 to surround body 25 and fit within container 21. The electrical connection 27 which supplies electric energy to the heater 26 is fed through a hole in container 21 to connect to the timer 14. The heater is shown as a blanket-type heater but can be any appropriate heating means so long as it fits within the space provided, is electrically isolated from the material defining the space, and adequately dries the desiccant material, such as silica gel 28, and filter means 29 are provided at each end of the body 25 to filter the fluid flow as well as confine desiccant material 28. The filter 29 can be spring loaded by a flat spring 30. Sufiicient movement of the spring load filter is allowed to compensate for settling or displacement of the desiccant. The head 24 has provided therein knockout portions 31 and 32 which provide ready choice of desiccant portions within the dehumidifier cabinet. For example, as seen in FIGURE 1, cartridge 12 has knockout 31 opened for the entry of the moist air inflow. Accordingly, cartridge 13 would have knockout 32 opened for the moist air inflow. This accommodates for the limited space Within the cabinet and eliminates the requirement of providing two types of cartridges. This two hole knockout provision enables other locating keying means to be utilized and overall convenience improved.

On the end of the bolt 22 is connected a flow valve 33 having a check valve 34 moved by spring 35 to close against abutment 36 when the fluid flow is not present. In the presence of a flowing fluid, check valve 34, moves away from abutment 36 to permit the direct flow of dry fluid into chamber 10. In the check valve 34, a capillary aperture 37 provides a continual flow of purge air in the non-flow direction of the check valve. Moisture that is removed by the heating of the desiccant is removed from the system through a selected setting of the three way input valves 15 and 16.

The desiccant and two filters are in the expandable cartridge 25.

The desiccant cartridge 12 is completely interchangeable with the desiccant cartridge 13. In a compact configuration, pipe 19 between valve 15 and cartridge 12 is spaced as close to pipe 19 between valve 16 and cartridge 13 as possible. This, however, results in the fluid entry into cartridge 12 above the center point and the fluid entry into cartridge 13 below the center point. The provision of the two knockout portions 31 and 32 accommodates for this dimensional difference while providing interchangeability of the cartridges.

The check valve 33 is located exteriorly of the cartridge for ease of removal. The important provision of an orifice drilled through the moveable portion of the permanently sealed check valve affords a controlled flow of purge air in the non-flow direction of the check valve.

FIGURE 3 shows the basic components of the desiccating structure of this invention. Cartridge 25 is shown with its front portion 24 with the heating blanket 26 removed therefrom. Also, container 21 is shown with lugs 38 thereon for mounting the container on the support structure of the system. The flow valve 33 is shown separated from the rest of the structure. It is readily seen that the cartridge is disposable and that the remainder of the structure is easily disassembled.

In FIGURE 1, the arrows indicating fluid flow are shown going in the same direction through desiccators 12 and 13. This indicates the free flow path that does flow in first one and then the other. At any single instant, however, if the free flow is as shown by the arrows through desiccator 12, then a much reduced flow will go through desiccator 13 in the opposite direction and expel moist fluid through the 3 day flow valve 16. Accordingly, opposite flows go through the two desiccators should desiccator 13 be the one through which the free flow exists.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood, that within the scope of the appended claim, the invention may be practiced otherwise than as specifically described.

What is claimed is:

In a closed controlled humidity system; a chamber in which the humidity is to be controlled; a pair of three way valve means; a pair of desiccating means; a pair of flow valve means; first fluid conducting means connecting said chamber to each of said three way valve means; sec ond fluid conducting means connecting a first of said three way valve means to a first of said desiccating means; third fluid conducting means connecting the second of said three way valve means to the second of said desiccating means; fourth fluid conducting means connecting said first desiccating means to one of said flow valve means; fifth fluid conducting means connecting said second desiccating means to the second of said flow valve means; and sixth fluid conducting means connecting each of said flow valve means to said chamber;

the improvement comprising:

a disposable sealed cartridge within each of said desiccating means, said cartridge having aperture means for ingress of moist fluid,

flow passage means for egress of dried fluid,

a pair of filter means, at least one of which has spring loading means,

a desiccating material confined within said cartridge between said filters,

retaining means secured to said flow passage means to retain said cartridge within said desiccating means,

each of said flow valve means having a housing means,

a fluid ingress means surrounded by a fluid flow sealing abutment,

a moveable valve means,

a compression spring loading means,

a fluid egress means surrounded by a spring support abutment,

said spring mounted under tension between said moveable valve means and said spring support abutment,

and aperture means in said moveable valve means aligned with said fluid ingress means to provide controlled flow of purge air in the non-flow direction of fluid through the check valve.

References Cited UNITED STATES PATENTS 2,569,537 10/1951 Robbins 163 X 2,623,607 12/1952 Bottum 55387 X 2,845,138 7/1958 Gageby 55387 2,979,828 4/ 1961 Westeren 5562 X 3,064,819 11/1962 Jones 55-387 X 3,192,686 7/1965 Berkey et al 5562 X REUBEN FRIEDMAN, Primary Examiner.

I. ADEE, Assistant Examiner. 

